Melatonin production is similar in children with monosymptomatic nocturnalenuresis or other forms of enuresis/incontinence and in controls

Purpose: Monosymptomatic nocturnal enuresis is a disorder, the precise etio logy and pathomechanism of which remain unknown. An elevated sleep arousal threshold leading to deep sleep, and an amplitude disturbance in circadian arginine vasopressin secretion and urine production have been suggested as possible causes of the disease. The pineal hormone melatonin is allegedly i mplicated in the physiological sleep mechanism and circadian system. Melato nin serum levels are high at night and low during the day. The major metabo lite of melatonin, 6-hydroxy-melatonin-sulfate (aMT6s), is excreted in the urine and is a good indicator of its production. We explore whether alterat ions in melatonin secretion assessed by its aMT6s excretion might be implic ated in the pathomechanism of monosymptomatic nocturnal enuresis. Materials and Methods: Urine was collected for 24-hour periods from 44 chil dren with monosymptomatic nocturnal enuresis, 10 children with other forms of enuresis/incontinence (nonmonosymptomatic nocturnal enuresis) and 25 con trols, and its aMT6s concentration was estimated using a commercially avail able radioimmunoassay. The total amount of aMT6s excreted per day was calcu lated. Results: We found no significant differences in the amount of aMT6s excrete d in a 24-hour period among patients with or without monosymptomatic noctur nal enuresis and controls with values of 17.6 mug. (1st to 3rd percentile 1 0.0 to 27.8) versus 13.4 (9.1 to 19.6) versus 21.5 (13.5 to 31.4), respecti vely. If aMT6s excretion was related to body weight, the result did not cha nge. Conclusions: Our data do not indicate that alterations in melatonin product ion might be involved in the elevation of the sleep arousal threshold assoc iated with deep sleep in children with monosymptomatic nocturnal enuresis.